1. Field of the Invention
The present invention is directed to vapor degreasing systems, and is more particularly directed to a cooling apparatus and methodology for use in a vapor degreaser which utilizes multiple chilling coils.
2. Description of the Related Art
Organic solvents/cleaning agents are used in various types of vapor degreasing/defluxing equipment to clean articles of manufacture, deflux electronic circuit boards, and the like. The organic solvents generally used are volatile organic solvents and fluorinated compounds using CFCs.
CFCs have been recognized to contribute to the depletion of the stratospheric ozone layer and to contribute to the global warming phenomena. In view of these damaging effects to the environment, the ozone-depleting solvents were replaced with hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs). The HCFC and HFC alternatives are generally more expensive and more physiologically active. Therefore, the traditional incentives to reduce vapor losses because of cost and safety were enhanced with the adoption of the HFC or HCFC solvents. Furthermore, with the use of these new cleaning agents, new parameters were required for various regions in the upper portion of degreaser tanks.
In view of the foregoing concerns, methods were developed in order to reduce vapor losses to the atmosphere and provide the tank conditions necessary for proper operation. This included the use of multiple cooling coil or heat exchanger configurations, also using non-CFC refrigerants.
In a multiple evaporator cooling configuration, the evaporators must operate at different temperatures. Currently, this is accomplished by providing each evaporator with its own condensing unit. However, this increases the number of cooling system components, thereby driving up the overall cost of the degreasing apparatus. In addition, the increase in the number of components results in an apparatus that is bulky and cumbersome and also impedes efforts to reduce degreaser sizes.
Therefore, it is one object of the present invention to provide a cooling system with multiple evaporators for cooling various zones of the degreaser tank at different temperatures without using a dedicated condensing unit for each heat exchanger. Additional advantages and features of the present invention will become apparent from the subsequent description and appended claims, taken in conjunction with the accompanying drawings.